Representation of problems during the conceptual design: A roadmap from functional to physical domains

International audienceConsidering that the representation of problems is a key step in the design of new technical systems, we propose a model of representation of problems. By integrating the problem solving between the functional modelling and the physical specification of the future system, we present a model enabling to build a bridge between these two domains. We will present in this article the model of representation of problems and the heuristics we use to instantiate this model. The use of one the heuristic will be illustrate by a study case

Les motifs de la participation électorale aux élections municipales québécoises : le cas de 2017

Chaire de recherche sur la démocratie et les institutions parlementairesÉlections QuébecÉlections Québe

Un cadre de conception centré utilisateur pour les systèmes de biofeedback

International audienceBiofeedback is defined as a technique that you can use to learn how to control the functions of your body. In essence, biofeedback gives you the power to use your physiological data to control your body, used frequently to improve a state of health or physical performance. We present in this article a summary of the components of the architecture of biofeedback systems based on literature. Then we offer a complete design framework to allow help to design systems with biofeedback.Le biofeedback est défini comme une technique que vous pouvez utiliser pour apprendre à contrôler les fonctions de votre corps. En substance, le biofeedback vous donne le pouvoir d’utiliser vos données physiologiques pour contrôler votre corps, souvent pour améliorer un état de santé ou de la performance physique. Nous présentons dans cet article une synthèse des composants de l’architecture de systèmes de biofeedback basé sur la littérature. Ensuite, nous proposons un cadre complet de conception pour permettre d’aider à la conception de systèmes avec biofeedback

Friction properties of fluorinated carbons

In boundary lubrication regime, friction reduction and antiwear processes are associated to the presence of additives in the lubricating oils or greases. These processes are due to the formation of protective tribofilms resulting from chemical reactions between the additives and the sliding surfaces, in the physico-chemical conditions of the sliding contact. Conventional antiwear additives mainly consist of transition metal organo phosphate or thiophosphates which present a remarkable efficiency in the case of contacts between ferrous alloys. In the case of non reacting surfaces, these additives become inactive. Recently developped lubrication strategies consist in the use of dispersion in oils of nano additives able to build the protective tribofilm in the sliding contact without reaction with the surfaces. Carbon fluorinated phases, due to their lamellar structure and their high chemical stability even at relatively high temperature (400°C) represent interesting candidates as lubricant nano-additives subjected to present friction reduction, anti wear and anti corrosion actions. This work presents the tribologic behaviour of some carbon fluorinated derivatives such as graphite fluorides, fluorinated carbon nanofibers, fluorinated carbon nanodiscs and fluorinated carbon blacks. The influence, on the tribologic performances, of the structure of the initial carbon phases, of the fluorination rate (0<F/C<1) and the structure of the fluorinated compounds is discussed